Tranny cooler woes

[iluv83vettes]

Its because you have low washer fluid.


I would put it on the gauge itself. You have a gauge in your other XJ right? I would try that one on it.

 

[xjtrailrider]

After reading the thread, my own 2 cents: I believe your sensor could be messed up, but I am a little confused though, you mentioned 2 B&M gauges, one for pressure, one for return, are they both indicating 260-ish (one 260 one 220)? It could be a bad wiring/ground if that happens. Also, the fact that they jump in big increments to 260 makes my suspicion even stronger.

Other than that, I have used so far 2 Tru Cool transmission coolers, with great results:
Big (40k CVW) LPD47391 (installed on a Liberty CRD)
Smaller (30K GVW) LPD49211 (installed on the Cherokee).

On the Cherokee, I had never seen more than 170 no matter what I do (I also have the same B&M gauge but I read the pressure line), no matter how many hours I am in city stop and go traffic or on one of my few times a year offroad. If you are thinking to upgrade, this is a great alternative.

And thanks for that Derale link, I didn't know thy make something like that, very cool idea!

I have one gauge and two senders. The senders are on a SPDT switch(could also be an issue, I might be reading both sensors at once?) So with the two sensors I can read pressure and return line temps at the flip of the switch. I agree, all my other XJ's stay in the 170-190 range.

Its because you have low washer fluid.


I would put it on the gauge itself. You have a gauge in your other XJ right? I would try that one on it.

Yes, I have the B&M gauge in two other XJ's here at the house but they are only sensing the return lines. I could try one of the other gauges but taking the AutoMeter pod off the A pillar can be a PITA though

 

[techno1154]

I have one gauge and two senders. The senders are on a SPDT switch(could also be an issue, I might be reading both sensors at once?) So with the two sensors I can read pressure and return line temps at the flip of the switch. I agree, all my other XJ's stay in the 170-190 range.



Yes, I have the B&M gauge in two other XJ's here at the house but they are only sensing the return lines. I could try one of the other gauges but taking the AutoMeter pod off the A pillar can be a PITA though

I have the identical setup that you have ie: one gauge, two senders and a SPDT switch. The only thing I noticed negatively about that setup is that it take a few seconds for the gauge to stabilize after the switch is flipped.

I Jacksonville afternoon stop and go traffic, I sometimes see 210* on the out put from the AW4 this past couple of weeks with STOP being more the rule than the exception. A flip of the switch show a 10 to 20* reduction through the cooler. Try to do an Ohm test on the senders and compare the readings with a know good sender. Also check the wires for chafing that could cause them to ground out. Is the sending unit located away from all other heat sources? What is the temperature of the fluid after the cooler? I think a 10to 20* reduction is normal.

And one more thing, make certain the senders are properly grounded as well as the gauge itself. On my XJ, the senders are in the metal line from the AW4. I had to run a dedicated ground to them both to get any kind of intelligent reading from them. If I were to finger any one item, I would say it is a grounding issue.

 

[xjtrailrider]

I have the identical setup that you have ie: one gauge, two senders and a SPDT switch. The only thing I noticed negatively about that setup is that it take a few seconds for the gauge to stabilize after the switch is flipped.

I Jacksonville afternoon stop and go traffic, I sometimes see 210* on the out put from the AW4 this past couple of weeks with STOP being more the rule than the exception. A flip of the switch show a 10 to 20* reduction through the cooler. Try to do an Ohm test on the senders and compare the readings with a know good sender. Also check the wires for chafing that could cause them to ground out. Is the sending unit located away from all other heat sources? What is the temperature of the fluid after the cooler? I think a 10to 20* reduction is normal.

And one more thing, make certain the senders are properly grounded as well as the gauge itself. On my XJ, the senders are in the metal line from the AW4. I had to run a dedicated ground to them both to get any kind of intelligent reading from them. If I were to finger any one item, I would say it is a grounding issue.

I have checked and rechecked the grounds, good there. My senders are located in brass T's which are hard plumbed with brass into the cooler, the cooler is mounted to the front cross member. In my last set-up I used a stacked plate Hayden and my senders were located in the hard lines and I had to run seperate grounds to those locations.

I'm getting the same results with my new set-up as what I got with the last set-up.

I went out tonight, started the Jeep up and let it idle for 5 min. and the temp "jumped" from ambient temp to 160?!?

I put my hand on the lines and they are cool!!!! I had the return line sender unhooked. I thought I might be drawing off of both senders somehow.

The gauge seems to be reading about 80* too high IMHO so I'm ordering another one.

 

[Boostwerks.com]

it might be worth the time to bypass the switch with a direct lead to the gauge just to make sure it isn't picking up both senders.

 

[xjtrailrider]

it might be worth the time to bypass the switch with a direct lead to the gauge just to make sure it isn't picking up both senders.

I have one sender disconnected right now and its still reading 140* after the jeep has been sitting for over an hour(even with both or either senders disconnected). When I first turn the key on I get a good reading on the gauge, right at or near 100*, but after a few minutes it "jumps" to 140*, if the Jeep is running and producing any heat it jumps to 160* just sitting at idle. I do not think a bad TC will cause a tranny to overheat at idle, correct me if I'm wrong.

I'm ordering another gauge tonight. I feel sure its the gauge now.

Some good came out of this fiasco. I now have a cooler that doesn't block the radiator anymore(the Derale is tucked in front of the front cross member and behind my winch bumper with a 7" puller fan in one of the cross member openings. So I'm getting flow from the road, the engine fans and the 400CFM minifan in the frame on the cooler)

This should help all around with cooling once I get a good read on it.

 

[xjtrailrider]

I forgot to add that when I changed the tranny filter, the pan was clean! The magnets only had a minor coating that I could have wiped clean with a tissue. I changed the filter in 2008 so its been a few years but only about 6k miles since this is a dedicated trail rig

 

[Prom3theus]

Since I have the same B&M gauge as you have, I remembered it coming with some instructions. I looked them up and on the "troubleshoot" section, this is what they say:

Reading too high -Power and ground wire reversed
Needle goes to extreme right -Lead to sender assembly accidentally grounded

this is the link of the PDF for the B&M gauge set:

http://static.summitracing.com/global/images/instructions/bmm-80212.pdf

I think since you're messing with the sender anyways, and also will need to take out the gauge (to replace it), it won't be a bad idea to double check all the wires (maybe they touch somehow in the gauge, or probe, or somewhere where you didn't see?), in both sender and gauge. The way I grounded my sender probe was to insert the ground wire in between the probe coupler (that mounts on the T-fitting and the probe screws in it) and the probe, so coupler (tight and sealed) in the T-fitting, then a 1/4 washer that stops on the coupler neck, then the ground wire soldered on an eyelet, then another 1/4 washer, then the sender, so the ground wire eyelet is very tight on the whole assembly by those 2 1/4 washers when you tighten the probe in the coupler. Then, I drilled a hole in the jeep chassis where I attached the ground wire. Good luck, I am curious if that ends up being a bad wiring or the gauge.

 

[xjtrailrider]

Since I have the same B&M gauge as you have, I remembered it coming with some instructions. I looked them up and on the "troubleshoot" section, this is what they say:

Reading too high -Power and ground wire reversed
Needle goes to extreme right -Lead to sender assembly accidentally grounded

this is the link of the PDF for the B&M gauge set:

http://static.summitracing.com/global/images/instructions/bmm-80212.pdf

I think since you're messing with the sender anyways, and also will need to take out the gauge (to replace it), it won't be a bad idea to double check all the wires (maybe they touch somehow in the gauge, or probe, or somewhere where you didn't see?), in both sender and gauge. The way I grounded my sender probe was to insert the ground wire in between the probe coupler (that mounts on the T-fitting and the probe screws in it) and the probe, so coupler (tight and sealed) in the T-fitting, then a 1/4 washer that stops on the coupler neck, then the ground wire soldered on an eyelet, then another 1/4 washer, then the sender, so the ground wire eyelet is very tight on the whole assembly by those 2 1/4 washers when you tighten the probe in the coupler. Then, I drilled a hole in the jeep chassis where I attached the ground wire. Good luck, I am curious if that ends up being a bad wiring or the gauge.

Very good advice I will do that!

So today I call up a local fellow XJ'er and borrow his infra-red thermometer. I took the Jeep out for a 3 mile drive to heat up the tranny. The B&M gauge is reading 260 off of the only sender hooked up, the one on the inlet side of the cooler. I hit the sender housing with the IR thermometer and I get 133*! The Cooler is showing 130* and the outlet side of the cooler is showing 115*!

So I either have a bad gauge or a wiring issue, both of which are easier to fix than dropping the tranny:clap:

I can handle that! I have been chasing this issue for a month now thinking I was cooking my tranny:doh: What a relief!

 

[Rainman]

I have a tranny temp gauge as well, however mine is in the sump.
I damaged my gauge one day when the wire came off at the sender and it shorted to ground while wheeling.
The gauge read high constantly afterwards.
So from my own experience I would say that grounding the sensor wire,while the gauge has power, fvks the gauge.
Good luck with it.

 

[xjtrailrider]

Problem still not solved

New gauge installed, it reads hot(not as hot) but 180 after a 1 mile drive. I shot the IR thermometer at the tranny lines at the sensors and got 120 on the inlet side of the cooler.

So I ran a new sender wire from the sender to the new gauge and took the switch and tranny output sensor out of the equation. It still reads hot but the IR says different.

I added a ground to the sender even though my ground was checking good at the sensor, still same results.

I checked my IR thermometer on various different things of know temp and it seems to read within 10 degrees of what it should. There is a 50-60 degree difference between the IR and the gauge.

I'm at a loss, is the IR wrong or are 2 temp gauges wrong?

 

[techno1154]

Back to the beginning,........Did you always have this problem? If not, when did it begin?

If all the wiring is good and the gauge is good that leave only incompatibility between the gauge and the sending units ie: the gauge and the sender were designed to work with each other. The first gauge and sender I bought was a set designed to work together. The second sender was bought months later. I made sure it matches the gauge with a range from 100 to 250. I know it is a long shot but it is easy to miss especially when one expect then to be compatible.

If that is not it, then it is time to sit back for a while and re-compose your self before removing every thing then re-installing them with a little more critical eye, looking a second time at every thing that appear to be questionable.

 

[xjtrailrider]

Back to the beginning,........Did you always have this problem? If not, when did it begin?

If all the wiring is good and the gauge is good that leave only incompatibility between the gauge and the sending units ie: the gauge and the sender were designed to work with each other. The first gauge and sender I bought was a set designed to work together. The second sender was bought months later. I made sure it matches the gauge with a range from 100 to 250. I know it is a long shot but it is easy to miss especially when one expect then to be compatible.

If that is not it, then it is time to sit back for a while and re-compose your self before removing every thing then re-installing them with a little more critical eye, looking a second time at every thing that appear to be questionable.

No, it started sometime this spring but I added the stacked plate cooler and dual senders over the winter. This is a trail rig and only gets driven to and from trail rides and during trail rides. i only test drove it this winter.

The two new senders are B&M, same as my original gauge. My new gauge is a "Equus" brand from Oriellys. I will switch the sender tomorrow just to be sure that is not the issue but the senders tested the same(I have a couple of old B&M senders laying around)

 

[xjtrailrider]

I just swapped the sender for the one that came with the new gauge and re-did the grounds at the senders. Fingers crossed!

 

[souske]

Is it a single wire sender?
are you using tape on the sensor? Tape messes with the grounding

 

[xjtrailrider]

Is it a single wire sender?
are you using tape on the sensor? Tape messes with the grounding

Yes, single wire. No tape, I learned that lesson years ago on a 5.0 Mustang I was building.

 

[hadfield4wd]

I told you how to fix this. Just go ahead and take the gauge out. Then run it.

 

[heavyequipment]

Synthetic trans fluid will take a lot more heat than regular petroleum, but the clutch seals, etc. may be affected by the heat. I use synthetic Red Line. Also, I made a trans cooler out of 4 lengths of 1/2" Copper pipe, joined with soldered ells and tees. It just fits on the outside of the R/H frame between the brackets. The inlet goes into a single tube at the front and returns to the front through 3 tubes. Then it goes to the radiator cooler to make sure it doesn't return too cold. I pull a 13' travel trailer on trips, so it works hard! Also, climbing long grades I use a low enough gear position to let it stay in lockup. It runs cooler that way.

 

[xjtrailrider]

Well, I went for a test drive tonight. It ran cool even on a warm night in stop and go. I think I got it to 230 once but it cooled back quickly. I was at the "Star City Cruise-In", one of the only XJ's out there and having a good time. I guess the stop and go was too much for it. But on the drive home, the front seal let go on the tranny. It is still in the "hot level" cross hatch but it was slightly overfull when I left the house and that might have done it. I had the level about 1/4" above the "hot level" cross hatch. The fluid did not come out the vent, its dripping from the bell housing and onto the exhaust. I killed mosquitoes for 5 miles on the run home. It still shifts fine like it always has.

For a XJ that has been stellar in reliability its really giving me fits right now. I do not think this Jeep want to go to Harlan KY and after working on little issue after little issue for the last 3 weeks, I'm not going to bother to try to swap the tranny right now. I need a damn break from working on this POS.

 

[Boostwerks.com]

How many miles are on the trans? Have you noticed any slippage? Even with some VB pressure mods and shift kit we still run roughly 150Deg with normal driving. Stop and go can get it up to 180-190, but hasn't passed 200. I have a mid size hayden cooler as well.

Before ruling out the trans, I would remove both cooler lines @ the trans and check for blockage. Also the fluid level is critical so this may have something to do with it. I would drain some out until the level is correct when fully warm, running, and in neutral.

Also be extremely careful with leaking atf! It is very flammable after all.

Hang in there!